Question Clicking noise from the PSU area ?

Ok, I've just had to import that sound into Audacity, and tweak it to bring the chatter sound to stand more clear from the background noise. There is this repeating rhythm, that at first glance can gives ideas of a drum set.

First - this almost rule out a fan issue. But have a visual check to see if the fan is actually spinning. If the fan spin seemingly at normal speed, you can rule out fan problem.

Relay? Well, some PSU may have a relay while other might not have one, depending of the design.

Does this sound change in intensity or frequency if you change the load (ie. running stress test) ?